234 Nelson : New Plants from Wyoming 



Some years since a large number of specimens of this species 

 were distributed (partly through the Minnesota Exchange Bureau) 

 as Aster canescens viridis Gray, under nos. 1 150 and 2788. More 

 recently it has been distributed as Machaer anther a canescens (Pursh) 

 Gray, which it is a long ways from being. It is, possibly, nearer 

 to Af. viscosa (Nutt.) Greene, but from that also it is at once sepa- 

 rated by its habit. From the former by the pubescence ; the 

 number and the position of the involucral bracts, and the color of 

 the rays. From the latter by the shape of the involucre and 



akenes. Th 



local. It is abundant in 



certain localities on the Laramie Plains but I have never collected 

 it outside of this range. I cite as type number 8152, Laramie, 

 Aug. 27, 1900. 



t/Rudbeckia ampla 



Perennial, from horizontal rootstocks with large fleshy crowns 

 from which spring numerous semi-fleshy roots : stems clustered, 

 f. <?., several from the same tuft, 1-2 m. high, glabrous, strongly 

 striate, moderately branched above : leaves numerous and ample, 

 light green and glabrous below, a shade or two darker above with 

 minute scattering hispid hairs from pustulate bases (the hairs some- 

 times deciduous), with conspicuous, light-colored veins : basal 

 leaves large, 2-3 dm. broad, trifoliate, on petioles 2-4 dm. long : 

 the leaflets petiolulate, broadly oval or ovate in outline, three-cleft, 

 the segments coarsely and irregularly serrate, the middle segment 

 often again lobed or cleft : lower stem-leaves similar but smaller, 

 the petioles becoming slenderer and shorter upward, the leaves 

 merely 3 -parted : upper stem-leaves sessile, 3 -parted or merely 

 cleft, 1-2 dm. long ; the segments becoming entire as to margin, 

 the lateral oblong-lanceolate, the middle variously toothed and 

 cleft : rameal leaves reduced, becoming entire and bract-like, from 

 broadly oval-acute to lanceolate : heads terminating the branches, 

 large : involucral bracts oblong to ovate, obtuse or subacute, 8-12 

 mm. long: rays 6-12, conspicuous, 3-5 cm. long, 8-15 mm. wide : 

 disk in full anthesis and in fruit cylindrical -ovate, 2-4 cm. high. 



That this is in part the R. laciniata of Gray's Syn. Fl. 262 is 

 possible but it is far from the typical eastern R. laciniata L. The 

 pinnately arranged narrow segments with wide sinuses of the 

 smaller leaves of that, need but to be compared with the trifoliate- 

 palmate broad segments and narrow sinuses of this to see that 

 they are distinct. The larger rougher disk, the fewer and stouter 



